1. Field of Invention
The present invention relates to a printer that has an opening/closing mechanism that opens while a platen disposed opposite a print head separates from the print head when the cover opens.
2. Description of Related Art
With roll paper printers used to issue receipts, for example, a length of printing paper pulled off the roll must be threaded through the paper transportation path between the print head and platen and between the paper feed roller and pressure roller to the paper exit. In order to simplify loading the roll paper, roll paper printers having an opening/closing mechanism that causes the platen disposed opposite the print head to open in conjunction with the cover so that the paper transportation path also opens when the cover of the roll paper compartment is opened are known from the literature. One type of known opening/closing mechanism is a four-part parallel linkage mechanism that opens away from the print head with the platen held positioned opposite the print head. Japanese Unexamined Patent Appl. Pubs. JP-A-2007-203563 and JP-A-2007-203564 teach a roll paper printer that uses a four-part parallel linkage mechanism to open and close the cover and platen.
When a 4-part parallel linkage mechanism is used, the platen frame on which the platen is disposed opens and closes with the cover while remaining in the same posture. As a result, when there are parts that protrude past the platen toward the print head, such as when gears, bearings, and a paper guide are supported on the platen frame, these protruding parts may interfere with the print head. In an inkjet roll paper printer, for example, the platen opposes the nozzle surface of the inkjet head with a predetermined gap therebetween. Therefore, if components that protrude beyond the platen toward the print head are mounted on the platen frame, these protruding parts may touch and damage the nozzle surface when the cover opens and closes.
A problem with a conventional opening/closing mechanism that uses a 4-part parallel linkage mechanism is that parts protruding beyond the platen toward the print head cannot be disposed to the platen frame to open and close together with the cover and the platen.
If such protruding parts are used in a serial inkjet roll paper printer, the cover must be opened and closed after confirming that the inkjet head has retracted to a retracted position removed from the printing area. In addition, when the inkjet head is in the printing area, the cover must be locked so that the cover cannot be accidentally opened and the protruding parts will not hit the nozzle surface of the inkjet head.